Last Wednesday I went to start the Plus 4 and the immobiliser light didn't go off when I clicked the ignition on. I knew the battery could do with a charge, so I charged it up overnight. The following day it started normally so I put this down to voltage sensitivity.
Yesterday, I wanted to fill the tank,so jumped in expecting a start, and the immobiliser light didn't go out.
So I removed the cowl to examine the sensor ring which surrounds the ignition lock barrel. This ring has a scientific name but rather than guess I'll call it the sensor ring. It detects the sensor which is buried inside the plastic part of the key. If you look carefully on the metal key side of the black plastic the location of the key sensor is visible as a filled hole.
The sensor ring around the lock barrel is secured by a neoprene spacer. Almost like I've been there before! I moved the sensor ring outwards, and the car started. It was a bit nail biting at the filling station but it started OK.
When we got back home I tried again and it wouldn't start............
So I consulted my Guru..........
The distance between the key and the detector ring is critical to probably within 1mm or less.
He's had a couple of Morgans in recently in the "18 months old to two years old range" with this issue.
The trick is to get the detector ring as close as possible to the key handle...............
This is how it comes from the Factory. The lock barrel is wrapped with standard density self adhesive neoprene. Around that to prevent the ring slipping inwards is a thin strip of neoprene. If your cowl is leather wrapped, the leather adds additional distance between the ring and key.
The next image is a bit clearer. The wiring from the sensor is a bit tight, but can be eased out from the cable tie buried under the dashboard.
The black plastic cover pulls off the lock barrel which makes removing the original neoprene much easier.........
The detector ring is upper left.
This is the DW solution. High density neoprene and with the securing ring held with a cable tie.
Refitting the cowl is tedious. I reduced the overlap of leather to try and reduce the thickness around the lock barrel. First time didn't work so I had to go back in and space the ring a little further out at the top.
If you ever get caught where the immobiliser light won't go out, wipe the black plastic part of the key around the lock barrel, and you'll have about twenty seconds to insert the key and start the engine after the light goes out!!!
Three starts later it looks promising, but who knows!!